JP2006033004A - Communication device, call processing control device, and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emergency call connection service capable of recall connection from an emergency command board upon a completion of the emergency report from an IP telephone set to the emergency command board of PSTN. <P>SOLUTION: A call processing control device 2 installed in an IP network is provided with a function 19 of receiving call connection information such as the call originator telephone number of a call subscriber and the call destination telephone number to detect an emergency report call subscriber, and a function 20 of managing the call connection information of the detected emergency report call subscriber. The control unit 17 of the device 2 uses this call connection information to control the restriction of the incoming call to the emergency report call subscriber and recall connection between the emergency report call subscriber and the emergency call board. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication device, a call processing control device, and a communication system, and more particularly to a communication device, a call processing control device, and a communication system for providing an emergency telephone connection service from an IP telephone.

  IP telephones based on VoIP (Voice over Internet Protocol) technology are rapidly spreading, and it is possible to realize interconnection with an existing public line telephone network (hereinafter abbreviated as PSTN: Public Switching Telephony Network). It was.

  The call connection between the PSTN and the IP network is described in Non-Patent Document 1. Specifically, in FIG. 5 of Non-Patent Document 1, there is a media gateway (hereinafter abbreviated as MG) that performs mutual conversion between PSTN STM (Synchronous Transfer Mode) voice signal data and IP voice packets: Media Gateway (SG), a signaling gateway (SG: Signaling Gateway) that connects to an IP network and transmits / receives common line signals, and MGCP (MGCP: Media Gateway Control Protocol) and other common line signals received by SG The PSTN and the IP are interconnected by deploying a call agent (hereinafter abbreviated as CA: Call Agent) that converts the signal into a signal, communicates, and performs MG control.

  When an IP telephone subscriber makes a call from an IP telephone to a PSTN subscriber telephone, the CA receives the calling telephone number and the called telephone number, and based on the high-order digits of the area number of the called telephone number. The IP address of the MG connected to the exchange accommodating the destination PSTN subscriber telephone is retrieved from the database, and the call connection is established with the MG according to the call connection protocol. Next, it is a call connection method in which a call can be made to a PSTN subscriber telephone via an exchange based on the called telephone number. In a large-scale IP network, a plurality of MGs and CAs are provided for the purpose of load distribution. In this case, information necessary for call control is communicated between CAs via the IP network.

  For PSTN telephone service, when a subscriber makes an emergency call to the police command board (110), fire department command board (119), etc., the calling subscriber is connected after the line connection between the reporting subscriber and the emergency command board. There is a line hold function for holding a line between a reporting subscriber and an emergency command board for a certain period of time, and a recall function for calling a report subscriber from the emergency command board even if the call is disconnected.

  On the other hand, an emergency call from an IP telephone has not been implemented because there is no realization method such as a line hold function and a recall function. As a countermeasure, in Patent Document 1, an adapter that switches between an IP network and a PSTN is installed in a subscriber's house, and when an emergency call is made from an IP telephone, the adapter automatically switches to a PSTN subscriber telephone. There is a description sent to the command board.

JP-A-10-257171 "Nikkei Communication", Nikkei BP, August 7, 2000, pp100-105

  However, due to the rapid spread of IP telephones, services similar to existing PSTN telephone services are also demanded for IP telephones. Specifically, when an emergency call is made, the IP telephone is required to recall the emergency command board to the caller. When this service is to be realized in a telephone network in which an IP network and a PSTN are interconnected, (1) when an IP telephone subscriber disconnects a call connection, the PSTN side must hold the line with the current line hold function. However, there is no way to hold the call connection on the IP network side. (2) Even if you try to call back to the caller from the emergency command board, the caller and the emergency command board side on the IP network side. There is a need to solve the problem that there is no way to make a recall connection.

  The object of the present invention is to reconnect the emergency command board and the calling subscriber after the call is disconnected between the caller and the emergency command board when the IP telephone subscriber makes an emergency call from the IP network to the emergency command board via the PSTN. It is to provide a possible communication device.

  A processing unit that receives caller information and callee information sent from an IP telephone set to a communication device connected to the IP network, and whether the telephone has issued an emergency call from the callee information And a storage unit for holding the call source information and connection information of the telephone network transmitted from another communication device connected to the IP network and the telephone network, and providing an emergency call. The connection information of the calling subscriber is retained even after the call is disconnected.

  According to the present invention, even when the IP telephone subscriber makes an emergency call from the IP network to the emergency command board via the PSTN in the telephone network in which the IP network and the PSTN are interconnected, after disconnecting the call between the reporting subscriber and the emergency command board, It is possible to provide an emergency telephone connection service for promptly reconnecting the emergency command board and the calling subscriber.

  Hereinafter, examples for explaining embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a diagram illustrating an IP network, a PSTN, and a common line signal network according to an embodiment of the present invention. FIG. 2 is a block diagram of the call agent according to the embodiment of the present invention. FIG. 3 is a diagram for explaining a table of the emergency call calling information storage unit of the call agent for explaining the embodiment of the present invention. FIG. 4 is a diagram for explaining a table in the CA information storage unit of the call agent that explains the embodiment of the present invention. FIG. 5 is a communication sequence diagram among the IP telephone, the call agent, the media gateway, the exchange, and the police command board for explaining an embodiment of the present invention. 6 and 7 are operation flowcharts of the call agent for explaining the embodiment of the present invention.

  FIG. 1 is a network in which an IP network 4, a PSTN 11, and a common line signal network 12 are connected. The IP network 4 is connected to the common line signal network 12 to connect the PSTN 11 to the common line signal and the call agent 2 is connected to the PSTN 11 exchange 8 to convert between the STM voice signal and the IP packet voice signal. And the IP gateway 1 is connected. On the other hand, the PSTN 11 includes an exchange 8, and a police command board 7 is connected to the exchange 8A.

  The IP network communication device is composed of two call agents 2A and 2B and media gateways 5A and 5B for the purpose of load distribution. The call agent 2 performs call connection control of the IP network 4, the call agent 2A controls the media gateway 5A, and the call agent 2B controls the media gateway 5B. The media gateway 5A is connected to the exchange 8A, and the media gateway 5B is connected to the exchange 8B.

  The call agent 2 shown in FIG. 2 includes an IP network interface 15, a call connection protocol processing unit 16, a detection storage unit 18, a common line signal network interface 14, a voice guidance transmission unit 23, and a CA control unit 17. It is configured. The detection storage unit 18 includes an emergency call call detection unit 19, an emergency call call information storage unit 20, another CA detection unit 21, and another CA information storage unit 22. Here, the IP network interface 15 is connected to the IP network 4 and transmits and receives IP packets such as control signals and voice signals. The call connection protocol processing unit 16 executes SIP (Session Initiation Protocol) defined by RFC 3261 of IETF as a call connection protocol.

  The common line signal network interface 14 is connected to the common line signal network 12 and transmits / receives common line signals to / from the PSTN 11. The voice guidance sending unit 23 sends voice guidance when a call connection request other than the recall connection between the emergency command board and the emergency call calling subscriber is made.

The detection storage unit 18 stores and manages information necessary for each call control. The emergency notification call detection unit 19 of the detection storage unit 18 detects call notification subscribers by monitoring the call connection information that the IP telephone subscriber calls. The emergency call calling information storage unit 20 stores call connection information of the calling subscriber when the emergency call calling detection unit 19 detects the emergency call calling subscriber. The other CA detection unit 21 inquires of the IP network 4 and detects another CA. The other CA information storage unit 22 stores other CA information detected by the other CA detection unit 21.
The CA control unit 17 controls the entire call agent 2.

  The call connection information of the calling subscriber stored in the emergency call calling information storage unit 20 is shown in FIG. 3, and the other CA information stored in the other CA information storage unit 22 is shown in FIG. The emergency call calling connection information management table 300 in FIG. 3 includes a calling source telephone number 30, an IP address 31, an exchange side connection information 35, a called telephone number 32, a recall flag 33, and a hold stop flag 34. ing. The other CA information management table 400 shown in FIG. 4 includes a CA number 40 and a CA_IP address 41.

How to provide the emergency telephone connection service in the network of FIG. 1 will be described with reference to FIGS.
First, call connection when the IP telephone 1A makes an emergency call from the IP network 4 to the police command board 7 via the PSTN 11 and disconnection of the call connection of the IP telephone 1A will be described.

  When the IP telephone 1A calls the police command board 7 (500), the call agent 2A receives the call from the IP telephone 1A by the call connection protocol processing unit 16 via the IP network interface 15. The call connection protocol processing unit 16 transmits call connection information such as a caller telephone number and a callee telephone number to the CA control unit 17 (600). The CA control unit 17 sends the acquired call connection information to the emergency call call detection unit 19, and the emergency call call detection unit 19 sends the emergency call of the IP telephone 1A from the destination telephone number of the received call connection information. A call is detected (601) and notified to the CA control unit 17. The CA control unit 17 stores the calling telephone number 30A, the IP address 31A, and the called telephone number 32A of the IP telephone 1A in the emergency call calling connection information management table 300. Thereafter, the CA control unit 17 restricts call connection processing of the stored caller telephone number 30A (the telephone number of the IP telephone 1A). Specifically, the call connection processing with the IP telephone 1A other than the police command board 7 is skipped (602).

  Next, the CA control unit 17 refers to the other CA information management table 400 of the other CA information storage unit 22 to determine whether another call agent is installed in the IP network 4 (603), and confirms that the call agent 2B exists. To do. The other CA information management table 400 detects the call agent 2B as a result of the other CA detection unit 21 making an inquiry to the other call agent of the IP network 4 via the IP network interface 15 in advance, and the call agent 2B A CA number 40A and a CA_IP address 41A are stored.

  The CA control unit 17 notifies the call connection information of the IP telephone 1A that has made an emergency call to the CA_IP address 41A of the call agent 2B via the IP network interface 15. Upon receiving the notification, the CA control unit 17 of the call agent 2B stores the call connection information of the IP telephone 1A in the emergency call call connection information management table 300 of the call agent 2B. Thereafter, the CA control unit 17 of the call agent 2B limits the call connection processing of the stored caller telephone number 30A (the telephone number of the IP telephone 1A). Specifically, the call connection process with the IP telephone 1A other than the police command board 7 is skipped. Thereafter, the CA control unit 17 of the call agent 2A performs call connection processing between the IP telephone 1A and the police command board 7 (605).

  The call connection from the IP telephone 1A to the police command board 7 will be explained. When the call agent 2A notifies the media gateway 5A of the IP address 31 of the IP telephone 1A (501), the media gateway 5A notifies the call agent 2A. The IP address assigned to the IP side, the port number and the channel number assigned to the PSTN side are returned, and the port on the IP network 4 side and the channel on the PSTN 11 side are connected (502). At this time, the call agent 2A stores the returned channel number (phone network connection information) assigned to the PSTN 11 side in the exchange side connection information 35A of the emergency call call connection information management table 300.

  Next, the call agent 2A transfers the call connection information on the PSTN 11 side to the exchange 8A via the common line signal network 12 (503), and the exchange 8A makes a connection request to the police command board 7 (504). A call is started in response to a response from the police command board 7 (505). Thereafter, when the IP telephone 1A disconnects the call, the call agent 2A detects the disconnection of the IP telephone 1A (506), and the call agent 2A sends a disconnect request via the media gateway 5A (507) and the common line signal network 12. The call is transferred to the exchange 8A (508), and the call is disconnected (509). On the PSTN 11 side after the call disconnection, the line used is held by the existing line hold function (510).

  Next, the recall operation from the police command board 7 after the call is disconnected will be described. First, when a recall signal is sent from the police command board 7 to the exchange 8A (511), the exchange 8A transfers the recall request to the call agent 2A via the common line signal network 12 (512). When receiving the recall request, the call agent 2A turns on the recall flag 33A in the emergency call call connection information management table 300 (607). Thereby, the recall connection process between the media gateway 5A and the IP telephone 1A is started, and the exchange side connection information 35A (channel number) stored in the emergency call call connection information management table 300 is notified to the media gateway 5A. (513). The media gateway 5A returns the IP address and port number assigned to the IP network 4 side to the call agent 2A, and connects the channel on the PSTN 11 side and the port on the IP network 4 side (514). The call agent 2A makes a call request to the IP telephone 1A (515). In response to the IP telephone 1A, a call by recall is started (516). Here, since the line on the PSTN 11 side is put on hold, it is possible to establish a call connection only by performing a call connection between the media gateway 5A on the IP network 4 side and the IP telephone 1A.

  Next, the operation of stopping the line hold function from the police command board 7 will be described. When the call is finished and the IP telephone 1A disconnects the call, the call agent 2A detects the disconnection of the IP telephone 1A (517), and the call agent 2A sends a disconnection request to the media gateway 5A (518) and the common line signal. The call is transferred to the exchange 8A via the network 12 (519), and the call is disconnected (520). When the operator of the police command board 7 determines that the line hold is not necessary, the police command board 7 sends a hold stop signal to the exchange 8A (521). The exchange 8A transfers the hold stop request to the call agent 2A via the common line signal network 12 (522). When the call agent 2A receives the hold stop request (608), the CA control unit 17 turns on the hold stop flag 34A of the IP telephone 1A in the emergency call connection information management table 300. Thereby, the call connection information of the IP telephone 1A stored in the emergency call call connection information management table 300 is cleared (609).

  In addition, when the CA control unit 17 confirms that the call agent 2B is present with reference to the other CA information management table 400 (610), the CA control unit 17 notifies the call agent 2B of the suspension stop request via the IP network interface 15. When the call agent 2B receives the hold stop request, the CA control unit 17 of the call agent 2B turns on the hold stop flag 34 of the IP telephone 1A in the emergency call calling connection information management table 300 of the call agent 2B. As a result, the call connection information of the IP telephone 1A stored in the emergency call call connection information management table 300 of the call agent 2B is cleared (611).

  Next, the operation of the call agent 2A when the IP telephone 1A makes a call to the IP telephone 1B will be described. The call of the IP telephone 1A is received by the call connection protocol processing unit 16 via the IP network interface 15, and the call connection information such as the caller telephone number and the callee telephone number is transmitted by the CA control unit 17. (600). The CA control unit 17 sends the acquired call connection information to the emergency call call detection unit 19, and the emergency call call detection unit 19 determines that the called telephone number of the received call connection information is not an emergency phone number. Then, the CA control unit 17 is notified (601). The CA control unit 17 refers to whether the caller telephone number of the IP telephone A is stored in the caller telephone number 30 of the emergency call call connection information management table 300 (612).

  As a result, if stored (immediately after disconnection of the call from the IP telephone 1A to the police command board 7), the CA control unit 17 determines that the call of the IP telephone 1A is a re-call after the emergency call, and the emergency call The recall flag 33A of the connection information management table 300 is turned ON. As a result, the recall connection process is performed on the IP telephone 1A by the same operation as described for the recall from the police command board (613). That is, the exchange side connection information 35A (channel number) stored in the emergency call call connection information management table 300 is notified to the media gateway 5A. The media gateway 5A returns the IP address and port number assigned to the IP network 4 side to the call agent 2A, and connects the channel on the PSTN 11 side and the port on the IP network 4 side. The call agent 2A makes a call request to the IP telephone 1A. Since the IP telephone 1A is already in a call state and the PSTN 11 is in a hold state, a call that is regarded as a re-call after an emergency call is started (516). In this case, the called telephone number of the IP telephone 1A is ignored.

  If not, it is referred to whether the called telephone number of the IP telephone 1A is stored in the calling telephone number 30 of the emergency call call connection information management table 300 (614). As a result, if it is stored (immediately after disconnecting the call from the IP telephone 1B to the police command board 7), the CA control unit 17 skips the call connection processing from the IP telephone 1A to the IP telephone 1B, and performs voice guidance. The voice guidance is sent from the sending unit 23 to the IP telephone 1A (615). If not stored, the CA control unit 17 performs normal call connection processing from the IP telephone 1A to the IP telephone 1B (616).

  Although the explanation is duplicated, immediately after the IP telephone 1A makes an emergency call to the police command board 7 and the IP telephone 1A disconnects (509), the call agent 2B makes a call from the IP telephone 1B to the IP telephone 1A. The operation will be described. When the call agent 2B detects a call from the IP telephone 1B (600), the call agent 2B determines that it is not an emergency call calling subscriber (601), and then the caller telephone number of the IP telephone 1B is the call agent 2B. It is determined that it is not stored in the caller telephone number 30 of the emergency call call connection information management table 300 (612), and the called telephone number of the IP telephone 1B is the emergency call call connection information management table of the call agent 2B. If it is determined that it is stored in the caller telephone number 30 of 300 (614), the call connection processing to the IP telephone 1A is skipped, and the voice guidance sending unit 23 of the call agent 2B sends a voice to the IP telephone 1B. A guidance is sent out (615).

  As described above, when an IP telephone subscriber makes an emergency call from the IP network to the emergency command board via the PSTN, the emergency command board and the reporting subscriber are quickly reconnected after the call disconnection between the caller and the emergency command board. Provision of emergency telephone connection service can be realized.

In the embodiment described above, the emergency command board is the police command board, but it may be a fire department, the Japan Coast Guard (No. 118), or another special number. The call processing protocol is not limited to SIP but is standardized by ITU-T. H.323 or other call processing protocol may be used. In addition, the call agent emergency call call connection information management table may be reset by the subscriber using a special number, for example.
The call agent may be called a call processing control device. Further, both the call agent and the media gateway are IP network communication devices, and may be communication devices in which the functions of both are integrated or communication devices in which the functions are redistributed. The functional block of the communication device may be realized by software.

It is a figure explaining the IP network of the Example of this invention, PSTN, and a common line signal network. It is a block diagram of the call agent of the Example of this invention. It is a figure explaining the table of the emergency call calling information storage part of the call agent explaining the Example of this invention. It is a figure explaining the table of CA information storage part other than the call agent explaining the Example of this invention. It is a communication sequence diagram among IP telephone, a call agent, a media gateway, an exchange, and a police command board explaining the Example of this invention. It is an operation | movement flowchart of the call agent explaining the Example of this invention. It is an operation | movement flowchart of the call agent explaining the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... IP telephone, 2 ... Call agent, 4 ... IP network, 5 ... Media gateway, 7 ... Police command stand, 8 ... Switch, 11 ... Public line communication network (PSTN), 12 ... Common line signal network, 14 ... Common Line signal network interface, 15 ... IP network interface, 16 ... call connection protocol processing unit, 17 ... CA control unit, 18 ... detection storage unit, 19 ... emergency call call detection unit, 20 ... emergency call call information storage unit, 21 ... Other CA detection unit, 22 ... Other CA information storage unit, 23 ... Voice guidance transmission unit, 30 ... Calling source telephone number, 31 ... IP address, 32 ... Called destination phone number, 33 ... Recall flag, 34 ... Suspended stop flag, 35 ... Exchange side connection information, 40 ... CA number, 41 ... CA_IP address, 300 ... Emergency call calling connection information management table, 400 ... Other CA information management table.

Claims (5)

A communication device connected to an IP network,
A processing unit for receiving call source information and call destination information sent from a telephone connected to the IP network;
A detecting unit for determining whether the telephone has made an emergency call from the called party information;
A storage unit for holding the caller information and connection information of the telephone network transmitted from another communication device connected to the IP network and the telephone network;
Including a communication device. A call processing control apparatus connected to an IP network and a common line signal network,
Detects that the IP telephone has made an emergency call to the telephone network from the call destination information from the IP telephone, and retains the caller information from the IP telephone and the connection information of the telephone network even after the call is disconnected And receiving a notification from the common line signal network to resume call connection between the IP telephone and the telephone network. A call processing control apparatus connected to an IP network,
A detecting unit that inquires about another call processing control device connected to the IP network;
A storage unit that holds the IP addresses of other detected call processing control devices;
A call processing control device. A communication system comprising a first communication device connected to an IP network and a second communication device connected to the IP network and a telephone network,
The first communication device includes a processing unit that receives call source information and call destination information sent from a telephone connected to the IP network, and the telephone issues an emergency call from the call destination information. A communication unit comprising: a detection unit that determines whether or not a call has been made; and a storage unit that holds the call source information and connection information of the telephone network transmitted from the second communication device. system. A communication system including an IP telephone, a call processing control device, and a media gateway,
After the IP telephone disconnects the emergency call to the command board, the call processing control device sends connection information of the telephone network to the media gateway in response to the re-request from the command board, and the media gateway A communication system, wherein an IP address and a port number assigned to a call are transmitted to the call processing control device, and the call processing control device makes a call request to the IP phone.

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